general problems of the 2021 Toyota Highlander - part 2

The contact owns a 2021 Toyota Highlander. The contact stated that while driving at various speeds and depressing the accelerator pedal, the contact heard an abnormal whining sound coming from the front of the vehicle. The vehicle was taken to an independent mechanic, where the contact was informed that it was a known failure. The vehicle was then taken to the dealer, where it was diagnosed, and determined that the transmission needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure and advised the contact to work with the dealer to have the transmission repaired. The failure mileage was 66,000.

I bought my 2021 Toyota Highlander on 11/17/2025 and approximately one month later, I heard a whining noise when the car accelerates past 25 mph. The whining noise gets progressively louder the more the car accelerates. In addition, when driving over a bump or hump, there is a grinding/creaking noise that occurs. I took my car into the Toyota dealership on 12/29/2025 and the service technicians were able to replicate my issues. They even stated that the issue is caused by a bearing failure inside the transmission. I also purchased an extended warranty but unfortunately the inspector sent by the warranty company wants me to get a transmission fluid exchange because they think that will solve the issue. The entire transmission needs to be replaced.

The transmission has developed a transmission whining noise which Toyota has released a TSB 0008-21. My vehicle has 104,000 miles and is now out of warranty. If this is a known defect on many Toyota vehicle models a transmission replacement should be free if no longer in warranty.

Whining sound upon acceleration. Occasional hesitation when shifting gears or rough shifting when going from complete stop to accelerating. Dealership says need new transmission. Warranty company test drove and agreed with dealership findings. 60,000 miles .

I brought my 2021 Highlander l in for some regular maintenance and reported that within the last 2 weeks I have been hearing a whining sound when the vehicle is decelerating. I was informed at the end of the day that the transmission is bad and needs to be replaced. My vehicle is just outside of warranty (69k miles). I have always ensured my Highlander got an oil change on time, had all recommended maintenance done at that appropriate time/milage, and brought it in for safety recalls promptly. This vehicle has never been in an accident, and while I have owned it (and according to carfax when I purchased it) I have always brought it to a Toyota dealership for any and all work. There have never been any warning messages, and even though my vehicle has been into Toyota regularly for oil changes and regular maintenance, I was never notified of any other issues. I also use this vehicle at least once a year for road trips (over 200 miles) and before every trip bring it in to have it checked. I'm being told it'll be about $10k to fix. Based on my research I have discovered this is a problem many people with a 2021 Highlander are having, also a class action lawsuit was filed due to transmission issues but only covered Highlanders up to 2020. This seems to be the same issues those vehicles had but I'm being told it's not covered or a recall.

Just after the 60,000 mile warranty, the car started making a whining noise when pushing the accelerator. This is part of the well known transmission problem. Transmission will need to be replaced.

Automatic transmission making humming noise while driving, can potentially fail without warning and leading to loss of power and potential crash.

My 2021 Toyota Highlander is experiencing a transmission issue causing a high pitched whining. It has the problematic ua80f. Toyota has declined to remedy the problem even with it being a known issue.

At around 70,000 mi the transmission started making noises and at the 80,000 mile marker I took it in for its maintenance they found debris in the transmission fluid and I was just told it's either a replace it now or replace it when it falls out of the vehicle. A vehicle with less than 100,000 mi and I am the only owner, for the transmission to go out or start going out and Toyota not solve problems is ridiculous.

Almost caused high speed accident merging onto toll road! the vehicle is experiencing a severe transmission slippage, shudder, and grinding noise, consistent with TSB-0008-21 (ua80 transmission failure). This defect causes hesitant acceleration and erratic shifting, creating a safety hazard when merging onto highways or crossing intersections. I am concerned the transmission will fail completely while driving, resulting in a sudden loss of motive power and increasing the risk of a crash. Toyota has covered this exact safety defect in 2017–2019 models (csp zjc) but has failed to recall the 2021 models despite identical symptoms. First reared it's head as slipping when putting vehicle in reverse, 25k+ ago. Was told by Toyota certified mechanics it was an operator error. Morphed into larger issue.

Transmission is making a loud whine when accelerating. Dealer says the transmission cannot be repaired and must be replaced.

2021 Highlander xle started making a whining noise when accelerating. Noise stops when you let off the gas. Took it to Toyota who said the transmission needed to be replaced. Although everywhere you look this is apparently a known problem, Toyota has yet to cover it or recall the part making the owners have to pay 9k to replace a transmission.

I am writing about my 2021 Toyota Highlander xle awd VIN # [xxx] . I purchased this vehicle brand new on 3/29/2021 at ‘koons easton Toyota’ in easton, MD. In October 2025 I started hearing whining noise from the engine compartment. It was audible only when accelerating the vehicle and would go away if I took my foot off the accelerator. On 10/22/2025, I took the vehicle for inspection to ‘ourisman Toyota 40’ dealership in edgewood, MD. The technician told me that this is a known issue in this model/year and recommended to replace transmission as there was no other fix. He gave me a $9,995 estimate for transmission replacement. I subsequently learned that there was technical service bulletin on this exact defect released by Toyota on 2/9/2021. It said that models with ua80f transmission will make whining noise and then fail. The only remedy was to replace the transmission with brand new transmission part number 30500-0e160. This bulletin was posted on NHTSA website also. [xxx] this bulletin was released 50 days before I purchased the brand-new vehicle on 3/29/2021. My frustration and disappointment came from the fact that Toyota had known about this issue for 50 days and still proceeded to sell this vehicle to me. This is unacceptable as there should have been a recall on this defect or Toyota should have pulled the vehicle from the market. This is not about the powertrain warranty running out as that would apply to unforeseen issues that neither manufacturer nor buyer knew about in advance. It is about knowingly selling the customer a defective product even after disclosing the major defect publicly. Transmission failure can be a serious safety issue because it could have caused sudden loss of power and difficulty controlling speed. I request NHTSA to investigate these widespread Highlander transmission issues the same way Ford f150 transmission issues are being investigated. Thanks information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

There is a known transmission issue with some 2021 Toyota Highlanders, avalons, and camrys. Toyota bulletin t-sb-008-21 from February of 2021 states 'some 2021 model year avalon, Highlander, and camry vehicles equipped with ua80e or ua80f transmissions may exhibit a whine or grind noise from the transmission. This condition may be caused by an issue with the front carrier assembly pinion shafts'. I have a 2021 Highlander with 127,000 miles that started to show this whine noise. Local transmission shop confirms that a new transmission is needed. I am taking it to a local Toyota dealer next week to confirm. I started a case online with Toyota USA, and since I'm over warranty, they started that will not assist with reimbursement. My complaint is how came a recall was not done on this? why did Toyota do nothing and now many of their customers with these vehicles face costly repairs ($7,000 - $12,000)? Toyota should at least reimburse their customers for some of the cost of the repair needed for this, even if out of warranty.

Hearing a whining noise when I step on the gas pedal. The Toyota dealership informed me I need a new transmission on a 4 year old vehicle with about 88,000 miles on it. Toyota said because there is no recall, they will not cover the replacement.

66,564 miles, transmission slipped and caused a delay in power, now it has a big high pitched whine and continues to do it. This looks to be a big problem across the board for 2021 Highlanders.

Transmission began producing a whine sound at 58k and slipped several times. . A transmission that slips could cause a wreck involving all passengers. Requires replacement. No warning lamps. Show some integrity Toyota and stand behind your products.

Noticed 2021 Toyota Highlander start whining around 85000 miles. Did some research on the sound and found that Toyota ua80f transmissions have all had the same issue and issued a TSB to their dealerships but not people who purchased the car. Warranty runs out and now you are on the hook for an 10k transmission replacement or risk your car breaking down at any point on the road. Car was inspected today by Toyota to receive the quote to fix at 10400 with no discussion of possible remedies for their defective transmissions. The exact quote would be "that's not our problem, you have to take it up with Toyota office, bud". So now we have a ticking time bomb on the road with the only remedy to pay 10400 to replace a defected transmission that was covered in other recalls by the same company.

Slipping and whining transmission while driving in the ozark mountains on [xxx]. I didn't feel I had full control of the vehicle. No warnings of any kind. Took the vehicle to saint charles Toyota service department on 10/2/25 where a bad transmission diagnosis was confirmed. Regards, [xxx] information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Transmisson started whining and slipping at 61000 miles. 1k miles out of warrenty. Even though Toyota has a service bulletin about knowing my exact year and serial number transmisson will go bad. No recall issued and they want 9k for a repair. Rick mcgill Toyota on alcoa highway knoxville tennensse diagnosed it.

Making a whinnig noise while accelerating.

2021 Toyota Highlander 87000 miles began making humming noise when stepping on gas and goes away when foot off gas. Toyota said metal shavings in transmission fluid and we need new transmission. We have made appointment to replace. No warning lights. No incident just filing complaint.

Vehicle had a very loud high pitch whining noise the rapid accelerated I was braking and brakes were not working vehicle screen was flashing vehicle malfunction. Yes vehicle is available. I could not stop the vehicle I struck three signs and a lady fell down as I was approaching the the building very fast, hit a wrought iron black fence and it fell on a park vehicle and then I hit a park vehicle and it stop I threw it in park. I am not sure. Insurance company after the vehicle accelerated there was a message saying vehicle malfunction, not before the accident.

At 65,000 miles, the transmission has developed a "whining" sound consistent with TSB t-sb-0008-21.

Entering the freeway a mile from home the car would not properly excellerate, only reachind 40 mph before exiting the freeway in favor backroads to my appointment. Shaking back and forth while driving, exacerbated when braking and coming to stop, I needed to put the car into neutral to calm down the shaking while waiting for the light to change. I just went through experiencing a brake failure and reporting of that to this agency and now see another of many defects associated with the 2020-2022 Toyota Highlanders and siennas Toyota is not addressing through recalls as they should be, and further frustrated this agency has or chooses to have no means by which to enforce Toyota's responsibility to the public.

Transmission failed and makes whining noise.

Started hearing a whining noise when I would accelerate and then my car bucked a couple of times. I brought it into Toyota on 8/07/25 to be checked out and I was told that my transmission would need to be replaced. My car is 4 years old, bought brand new in April of 2021 and have kept up on regular maintenance. In researching this I am finding out that there is a large number of people who are experiencing this same thing with their Highlanders. I have also come to find out that in February of 2021 there was a TSB put out with regards to this same issue. This was 2 months before I even purchased my car. It for some reason does not include every vehicle and only some vehicles are included leaving others with this problem out of luck. I do not understand how that can be. If I have that ua80f transmission in my car and that is what is being named as one of the transmissions that have this problem then why is that certain vehicles are not being taken care of and why is Toyota not issuing a recall? my warranty has expired so I am being expected to pay out of pocket $8,000 (not including labor) and on top of that they do not even have the parts as they are on back order. We have to hold Toyota responsible for this.

Whine when accelerating. Toyota has released a TSB 0008-21 indicating to replace transmission due to incorrect installation of a retaining clip on a nut securing differential in place. Nut can become loose and stuck in gears of internals of transmission causing transmission to lock up while driving. This will cause loss of power and could result in an accident. Toyota is aware of the issue but refuses to make repairs due to vehicle being outside of powertrain warranty. Toyota has extended warranty to 10 years on 2017 and 208 model years however the problem still exist in 2017-2024 model years with the same transmission ua80e/ua80f.

Complete failure of transmission at approximately 53k miles. No warnings. No lights. Car had just had its 50k miles service appointment. My safety and that of my family was jeopardized when I unknowingly took this car to/from our family vacation out of state- the gears started jumping a few days after we returned, quickly followed by the grinding, whining noises. Come to find out there is a service bulletin that has been out for 4 years! t-sb- 0008-21 issued on February 9, 2021, for select 2021 Highlander models equipped with a ua80e or ua8of. 8-speed automatic transmission. Why wasn't this a recall? how is this not a safety issue? why wasn't this disclosed by Toyota when I was sold a car with 30k miles on it for $35k miles?.

Our vehicle has 72k miles at normal use- no towing or off roading. Due to a whining noise we took in the vehicle at a Toyota dealer and after a $200 diagnostic fee concluded we need a new transmission priced at $10,800. There was no explanation/diagnosis summary- just we need a new transmission.

Vehicle starts to produce humming and whining sounds as speed picks up from underneath the vehicle, likely from the transmission/final drive gear area. This problem is consistent and persistent. The whining noise stops when the throttle is released and will resume as throttle is engaged. More reported cases of transmission failure, sudden lost of propulsion and grinding noise are found on public forums. Toyota issued a service bulletin about this problem. Toyota issued extended warranty to prior model years from 2016 to 2017 of the same issue. This will affects millions of Toyota sold with the ua80, ua80e and ua80f transmissions in the us.

At 119,000 miles, the ua80f transmission in our 2021 Toyota Highlander xse started making a whining noise. A dealer confirms the transmission needs to be replaced. After much research, this is apparently a known issue and Toyota will not warranty the repair after the 60,000 mile warranty expires. Estimated repair cost is $11,000.

Winning sound coming from the transmission - upon seeking information online I was able to find a service bulletin from 2021 that addresses the issue - I see a large number of posts online with people having the same issue - the only solution is a transmission replacement - Toyota should be made to do a recall on these vehicles.

There is a known defect with transmissions in certain model years of Toyota cars, mine being one of them, per this TSB: [xxx] the transmission can catastrophically fail but Toyota will not replace the defective part unless the vehicle is still under warranty. I had the Toyota dealer verify that the transmission is beginning to fail and requires replacement. The transmission has begun to emit a "whining" noise. Should the transmission fail catastrophically during operation, it could cause a sudden loss of power, seize a drive wheel, or another event causing a loss of vehicle control. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Whine noise when vehicle is in motion and accelerating. Took it to the dealer for inspection, and advise to replace the transmission.